This invention generally relates to reclosable packaging. In particular, this invention relates to reclosable packaging having an external shroud or header that covers a plastic zipper or fastener.
Reclosable fastener assemblies are useful for sealing pouches or bags. Such fastener assemblies often include a plastic zipper and a slider. Typically, each zipper comprises a pair of interlockable fastener elements, or profiles. As the slider moves across the profiles, the profiles are opened or closed. The profiles in plastic zippers can take on various configurations, e.g. interlocking rib and groove elements having so-called male and female profiles, interlocking alternating hook-shaped closure members, etc.
Gusseted bags having thermoplastic zippers are well known in the reclosable packaging art. One advantage of such gusseted bags is that they may be opened more fully to facilitate filling the bag and later removing its contents. In some designs a gusseted side of the bag can be used to form a pouring spout by pulling the gusset outward and then inverting the bag, in which event the pourable contents of the package can be made to pour down the V-shaped channel formed by the gusset panels.
In the pet food industry, dry pet food is often packaged in a gusseted bag made of a laminated material. The outermost layer of the laminate is made of paper having a finish suitable for printing thereon. The innermost layer of the laminate is a sealant layer made of plastic material. This sealant layer allows the contents of the bag to be hermetically sealed to maintain freshness. An intermediate layer of the laminate is made of brown paper.
U.S. patent application Ser. No. 10/759,800, entitled “Easy-Open Shrouded Slider-Zipper Assembly for Reclosable Bag”, discloses a shroud comprising a folded web having an inverted U-shaped profile that covers a slider-zipper assembly, the zipper of which is heat sealed to the shroud. In accordance with the disclosed method of manufacture, the free sides or legs of that shroud are inserted into the mouth of the receptacle. In that position, thermoplastic exterior surfaces of the sides of the shroud are heat sealed to thermoplastic interior surfaces of the receptacle. In the completed package, the shroud covers the zipper in a manner that provides evidence of tampering.
There is a need for alternative methods of making a reclosable package of the type disclosed in the preceding paragraph.